Division of Compensation Analysis and 

Support 

Program Evaluation Report

Document Number: DCAS-PER-048 

Effective Date: 9/27/2013 

Revision No. 0

Wah Chang Page 1 of 2 

Author: Signature on file Date: 9/27/13 

 Dave Allen, HP Team Leader 

Approval: Signature on file Date: 9/27/13 

 J.W. Neton, Associate Director for Science

Supersedes: None

RECORD OF ISSUE/REVISIONS 

ISSUE 

AUTHORIZATION 

DATE 

 

 

9/27/2013

EFFECTIVE 

DATE 

 

9/27/2013 

REV. NO. 

0 

DESCRIPTION 

New document to determine the effect 

on previously completed claims due to 

changes to Wah Chang dose 

reconstructions. 

1.0 Description 

No Technical Basis Document exists for Wah Chang claims. The following 

changes, however, have occurred that could affect claims from this site: 

 The dates of the operational and residual periods have changed; 

 A Special Exposure Cohort was designated; and , 

 Some previous dose reconstructions utilized values from ORAUT-OTIB-0070 

which was revised on 3/5/2012. 

2.0 Issue Evaluation 

The change to operational and residual periods for Wah Chang occur prior to the first 

Wah Chang dose reconstruction being drafted and only reduced the operational and 

residual periods for the site. Therefore this change would not affect any previously 

completed claims. 

The designation of a Special Exposure Cohort for Wah Chang occurred on April 29, 

2011. The designation determined that NIOSH was unable to estimate internal and 

external dose from thorium during the entire covered period which is designated from 

1/1/1971 to12/31/1972. During the SEC evaluation process, additional information was 

discovered and used in subsequent dose reconstructions. The information consisted of a 

contemporary estimate of the amount of uranium remaining in the arc furnace after the 

weapons related work in 1971 and 1972. The resulting external dose estimate starting in 

the residual period was higher for some job categories of workers. 

Also, Wah Chang dose reconstructions utilized ORAUT-OTIB-0070 to estimate the 

reduction of residual contamination over time following the end of weapons related 
Division of Compensation Analysis and 

Support

Program Evaluation Plan

Document Number: DCAS-PER-048

Effective Date: 9/27/2013 Revision No. 0 Page 2 of 2

operations. This document was revised on 3/5/2012 lowering the contamination 

reduction rate. This causes the dose estimates to increase in some years of the residual 

period.

 

3.0 Plan for Resolution or Corrective Action

Since almost all Wah Chang claims included employment in the residual period and since 

the last change (ORAUT-OTIB-0070 revision) affected the residual period dose 

estimates, all claims with Wah Chang employment and a probability of causation less 

than 50% were considered. Those completed after the revision to ORAUT-OTIB-0070 

were reviewed and eliminated if the current version of ORAUT-OTIB-0070 was used. 

The dose for the remaining 114 claims was recalculated using all currently approved 

methods and information. During this process, one claim was returned by the 

Department of Labor based on an additional cancer diagnosis. Since a new dose 

reconstruction was to be calculated using current methods, the claim was eliminated from 

further consideration for this PER.

As a result of this process, dose for all of the 113 remaining claims was recalculated and 

all resulted in a probability of causation below 45%.

NIOSH will provide the Department of Labor with the identity of the claims evaluated under 

this PER.